Source : WordNet®

subbing
     n : working as a substitute for someone who is ill or on leave
         of absence [syn: {substituting}]

sub
     n 1: a large sandwich made of a long crusty roll split lengthwise
          and filled with meats and cheese (and tomato and onion
          and lettuce and condiments); different names are used in
          different sections of the United States [syn: {bomber},
          {grinder}, {hero}, {hero sandwich}, {hoagie}, {hoagy}, {Cuban
          sandwich}, {Italian sandwich}, {poor boy}, {submarine},
          {submarine sandwich}, {torpedo}, {wedge}, {zep}]
     2: a submersible warship usually armed with torpedoes [syn: {submarine},
         {pigboat}, {U-boat}]
     [also: {subbing}, {subbed}]

sub
     v : be a substitute; "The young teacher had to substitute for
         the sick colleague"; "The skim milk substitutes for
         cream--we are on a strict diet" [syn: {substitute}, {stand
         in}, {fill in}]
     [also: {subbing}, {subbed}]

subbing
     See {sub}